ULYSSES OBSERVATIONS OF AURORAL HISS AT HIGH JOVIAN LATITUDES

During the Ulysses flyby of Jupiter, a whistler-mode emission was peri odically detected by the Unified Radio and Plasma wave (URAP) experime nt during intervals when the spacecraft extended to high magnetic lati tudes. The signal was detected between the local electron plasma frequ ency and lower hybrid resonance and appears as a funnel-shaped structu re on frequency-versus-time spectrograms; these characteristics are ve ry reminiscent of whistler-mode auroral hiss observed at high latitude s at Earth. Ray tracing of the emission occurrences suggests the emiss ion source is on magnetic field lines extending out to at least 65 R(J ). This location associates the emission with the boundary between ope n and closed field lines - not the Io torus. The emission radiates abo ut 10(7) W of power. Consequently, the auroral input power derived fro m the solar wind to drive the emission is believed to be 10(10-12) W ( or about 1% of the energy associated with lo torus electrical processe s).